What Is a Chimney Cricket? (Signs, Cost & Code Explained)

A chimney cricket is a small, sloped structure built on the uphill side of a chimney. Its job is to divert rain, snow, and debris around the chimney so they don't pool against the flashing.

You may also see it called a chimney saddle or roof cricket. All three terms describe the same feature.

This guide covers what a chimney cricket does and when your roof might need one, along with the building code requirement and the warning signs to watch for.

What Does a Chimney Cricket Actually Do?

A chimney cricket's job is simple: move water around the chimney instead of letting it collect there. That one function creates a few practical benefits for the roof and chimney.

• Protects the masonry and flashing. Water no longer pools on the uphill side of the chimney, so it can't work behind the flashing or soak into the brick.
• Cuts down on ice dams. In cold, wet climates like the Pacific Northwest, standing water behind a chimney is exactly what leads to ice buildup.
• Keeps debris from collecting. Leaves and needles that pile up behind a chimney hold moisture against it. A cricket sheds that debris along with the water.
• Discourages pests. Standing water and debris are what draw birds, squirrels, and insects to the base of a chimney. Take away the pool, and you take away the draw.

Do You Need a Chimney Cricket? Building Code Requirements

The International Residential Code and International Building Code set the trigger at 30 inches, in Section 1503.5, Crickets and Saddles. Any chimney or roof penetration that wide or wider needs a cricket or saddle on its high side.

Washington and Oregon base their local codes on this model code. Some jurisdictions adopt amended versions, so it's worth having a roofing contractor confirm the exact requirement during a roof inspection.

In plain terms, most narrow chimneys fall under that 30-inch line and don't legally need a cricket. Wider chimneys, and chimneys on low-slope roofs, often need one anyway. Water backs up quickly behind a wide, flat obstruction, code requirement or not.

Signs Your Roof Needs a Chimney Cricket

A few warning signs point to a chimney that could use a cricket. Some show up inside the house, others are visible from the ground.

• Water stains or leaks near the chimney. Interior ceiling stains close to the chimney often trace back to water backing up on the roof's uphill side. If you're already seeing damage indoors, it's worth having a roofer look at repair options at the same time as the cause.
• Standing water, moss, or debris after rain. From the ground, you may spot pooling or debris buildup on the chimney's upslope side after a storm.
• Ice buildup or icicles behind the chimney. In winter, ice that concentrates behind the chimney usually means water is collecting there instead of draining away.
• A wide chimney with no visible diverter. If a chimney is wider than 30 inches with no peaked structure behind it, code may require a cricket that isn't there.

A roofing contractor can confirm these signs with a closer look. Some are easier to spot up close than from the ground.

Chimney Cricket vs. Chimney Flashing: What's the Difference?

A cricket and flashing solve different parts of the same problem. Flashing seals the joint where the roof meets the chimney, keeping water from seeping through that seam. A cricket works further upstream: it redirects water before it ever reaches that joint.

The two work together rather than substitute for each other. A cricket reduces how much water flashing has to handle. That matters most on wide chimneys, where water would otherwise pool and push against the seal.

If your chimney's flashing needs repair, a cricket can ease some of that pressure going forward, rather than putting the same load right back on a fresh repair.

Materials and How Crickets Are Built

A chimney cricket starts as a wood frame, built to the correct pitch, then covered to match the surrounding roof. On most homes, that covering is asphalt shingle, matching the rest of the roof.

In high-flow spots, roofers often switch to metal or a membrane material like PVC or rubber instead. These hold up better where a lot of water passes through.

That upgrade shows up often in the Pacific Northwest. Even on shingle roofs, roofers here tend to cover the cricket in metal or membrane, since local rainfall pushes more water through that one small area than a typical roof handles.

Cost to Install a Chimney Cricket

The cost of a chimney cricket depends mainly on two things: how wide the chimney is and what material covers the roof. A wider chimney means a larger cricket, which means more material and labor. A cricket covered in metal or membrane costs more than one finished in asphalt shingle to match the roof.

Timing also affects the price. Adding a cricket during a full roof replacement is typically a modest add-on to that project, since the roofing crew is already framing and covering the area. Retrofitting a cricket onto an existing roof as a standalone project tends to cost more, since it requires opening up a section of roof that would otherwise stay untouched.

A roofing contractor can give you an exact number after seeing the chimney's width, the roof material, and whether the work is part of a larger project.

DIY vs. Professional Installation

A chimney cricket is not a simple add-on. It's a structural roof modification that has to tie into the existing flashing correctly, or it can create a new leak instead of fixing the old problem.

Framing the cricket to the right pitch, integrating it with the chimney flashing, and matching the roof covering all take roofing experience most homeowners don't have on hand. A cricket that's built or installed incorrectly can send water into areas of the roof that were never a problem before.

For that reason, cricket installation is typically left to a roofing contractor rather than handled as a weekend project. It's a case where getting it right the first time matters more than saving on labor.

Chimney Crickets on Older Portland Homes

A chimney cricket is a small structure with a big job. It keeps water, snow, and debris from pooling against the uphill side of a chimney, which protects the flashing and masonry underneath.

Many older homes in the Portland area have chimneys built before current cricket requirements were common. If you're due for an inspection, our Portland roofing services team can check for one while they're already on the roof.

If you're noticing water stains, standing water, or ice buildup near your chimney, a roofing contractor can take a closer look and explain whether a cricket, a flashing repair, or both would solve the problem.

FAQ

What is another name for a chimney cricket?

A chimney cricket is also called a chimney saddle or roof cricket. All three names describe the same sloped structure that diverts water around a chimney.

Is a chimney cricket required by code?

Building code generally requires one on chimneys 30 inches or wider, measured along the ridge. Narrower chimneys may not need one by code, but they can still benefit from one in a high-rainfall climate.

Can a chimney cricket be added to an existing roof?

Yes. Adding a cricket is a common retrofit during a roof replacement, and it's also done when recurring leaks trace back to the chimney's uphill side.